Effect of molybdenum on nodulation, plant yield and nitrogen uptake in hairy vetch (Vicia villosaRoth)

Abstract

Hairy vetch (Vicia villosa Roth) is a leguminous cover crop that is generally used as a green manure to sustain soil health in arable land. Molybdenum (Mo) acts as a cofactor for the nitrogenase (NA) and nitrate reductase (NR) enzymes, which are important for nitrogen (N) fixation, nitrate reduction and N transport in plants. In this study, we applied various doses of Mo to soil to evaluate their efficacy on nodulation, nodule characteristics and biomass production of hairy vetch. Mo application increased the number and size of nodules and NA and NR enzyme activity in hairy vetch. This increase in enzyme activity increased N assimilation and led to higher biomass yield. Plants grown in soil that received 0.5 mg Mo kg −1 showed optimal physical and biochemical properties in nodules, and these properties may explain the increased N fixation in hairy vetch. Higher Mo doses (1.0 mg kg −1 ) led to the deterioration of nodule structure and, hence, reduced enzymatic activity in plants. The 16S rRNA gene sequencing and cluster analysis showed that the bacterial isolates found in the nodules of hairy vetch roots belonged to the Rhizobiaceae family and shared high sequence similarity with Rhizobium leguminosarum and Agrobacterium tumefaciens. Application of 0.63 mg Mo kg −1 to soil was the optimum dose to maximize the biomass yield of hairy vetch.

LjMOT1, a high‐affinity molybdate transporter from Lotus japonicus, is essential for molybdate uptake, but not for the delivery to nodules

“…Mo is involved in nitrogen assimilation in plants, and Mo application increased the number and weight of nodules, as well as NA and NR enzyme activity, in soybean and hairy vetch (Kanaan et al, 2013;Alam et al, 2015). Therefore, the effects of LjMOT1 mutation on processes of nodulation and nitrogenase activity were investigated.…”

Micronutrient deficiencies in African soils and the human nutritional nexus: opportunities with staple crops

“…The application of moderate amounts of boron up to 3 kg ha -1 increases soil fungal and bacterial populations, and phosphatase and dehydrogenase enzyme activities by between 18 and 34% during different growth periods relative to no application (Bilen et al 2011). Application of 0.5 mg kg -1 of Mo increased nitrogenase enzyme activity (71%) and root nodule number (63%; Alam et al 2015), while application of moderate Zn (15 kg Zn ha -1 ) increased nodule indices of cowpea by at least 38% (Upadhyay and Singh 2016). At high concentrations, for example, of boron (application of 9 kg B ha -1 ), the microbial growth and enzyme activities decrease due to impaired functions of cell membrane, and soil microbial structure is altered (Nable et al 1997;Nelson and Mele 2007;Bilen et al 2011;Vera et al 2019).…”

A community perspective on the concept of marine holobionts: current status, challenges, and future directions

“…The integration of this knowledge into agricultural practices has led to substantial yield improvements (e.g. Kavimandan 1985;Alam et al 2015). In the more diffuse and partnerrich system of mycorrhizal symbioses between plant roots and soil fungi, a better understanding of the interactions has also been achieved via the investigation of environmental diversity patterns in combination with experimental culture systems with reduced diversity (van der Heijden et al 2015).…”